乔山林区油松林是陕北种子基地之一,但由于油松球果小卷蛾(为主要虫种)、油松球果螟、松梢螟的危害,油松球果被害率以往一般达70%,今年调查,油松球果被害率达64.8—86.5%(见表1),造成油松种子大幅度减产,影响育苗、造林的发展。同时,危害嫩梢,使嫩梢秃顶或干形不正,不能长成高大用材。 The Pinus tabulaeformis forest in Qianshan forest area is one of the seed bases in Northern Shaanxi. However, the damage rate of Pinus tabulaeformis was generally as high as that of Pinus tabulaeformis (the main species), Pinus taeda, 70%, this year’s survey, pine cones damage rate of 64.8-86.5% (Table 1), resulting in a substantial cut of pine seeds, affecting seedling, afforestation development. At the same time, endanger young shoots, make young shoots bald or dry shape is not correct, can not grow into tall timber.